Analysis of wave number spectra through the terrestrial bow shock

Evolution of the magnetic field fluctuations of the solar wind across the Earth’s bow shock is studied. Using the four Cluster spacecraft the energy spectra of the magnetic field fluctuations are decomposed into three distinct components in the wave number domain: two-dimensional component, Alfv´enic component, and compressible component. The spectral decomposition provides a means to study how the shock-turbulence interaction occurs in the collisionless plasma. The two-dimensional component is a major contributor in the fluctuation energy throughout from the solar wind to the foreshock, the magnetosheath, and the cusp region. The solar wind exhibits the dominance of the two-dimensional component and its wave number spectrum is characterized by a power law with the index close to -5/3. The transition of the solar wind across the shock is characterized not only by amplification of the fluctuations but also by reconfiguration of the energy contributions of the three components. The foreshock and the magnetosheath exhibit enhancements of the Alfv´enic and the compressible components, respectively. The reconfiguration of the energy contribution can be interpreted in such a way that the solar wind turbulence is modified by the waves that are locally excited by the shock-reflected ions or directly by the shock.

@article{id1306,
  author = {Narita, Y. and Glassmeier, K.-H. and Gary, S. P. and Goldstein, M. L. and Treumann, R. A.},
  doi = {10.1029/},
  journal = {Journal of Geophysical Research Space Physics},
  language = {en},
  title = {Analysis of wave number spectra through the terrestrial bow shock},
  volume = {113},
  year = {2008},
}

%O Journal Article
%A Narita, Y.
%A Glassmeier, K.-H.
%A Gary, S. P.
%A Goldstein, M. L.
%A Treumann, R. A.
%R 10.1029/
%J Journal of Geophysical Research Space Physics
%G en
%T Analysis of wave number spectra through the terrestrial bow shock
%V 113
%D 2008